Method of hardening and toughening metal.



" UNITED STATES PATENT OFFICE.

HENRY W. PARTIN, OE PORTSMOUTH, VIRGINIA.

METHOD or nannnnme AND TOUGHENING METAL.

937,263. NoDrawing.

To all whom it may concern:

Be it known that I, HENRY W. PARTIN, a citizen of the United States, residing at Portsmouth, in the. county of Norfolk and State of Virginia, have invented certain new and useful Improvements in Methods of Hardening and Toughening Metal, of which (the. following is a specification. V

- My invention relates to an improvement in amethod for hardening and toughening tools of ironor steel used for any class of work such, for instance, as cutting or punching.

The object of the invention is to harden and toughen tools by subjecting them to a certain process which, will be hereinafter described, making the tool much harder and tougher than tools now used, thus permittin them to be used for many purposes for which the ordinary tool could not be used, and in performing these functions the tools are in no wise injured for' further use.

A further object of the invention is to harden and toughen any kind of metal, such as armor plate, iron or steel rails, and other I similar articles of manufacture.

The tool or metal previous to its treatment is brought to the proper heat, which'is different (with different articles, some articles requiring greater heat than others. The metal or tool while in this heated condition is rolled or dipped into a compound consisting of pulverized borax, bicarbonate of soda, common salt, and salts of cobalt mixed in equal proportions. The metal when in. its heated condition will absorb the compound or powder as the heat opens up the pores, so thatthe com ound passes entirely through the metal, and the metal becomes toughened. I am enabled to use only borax and bicarbonate of soda toobtain results, but prefer to combine the hora-x and sodawith common salt, omitting the cobalt or including both salt and cobalt with the soda and borax.

After the heated metal has been dipped, rolled, or has received the powder or compound thereupon in any approved manner it 1s then immersed in a solution consisting of the following ingredients: fifty allons of water; one-half pound of lime, either shell orv rock lime; one ounce of sal ammoniac; one ounce of bicarbonate of soda one ounce of Specification of Letters Patent.

Application filed September 10, 1908. Serial No. 452,479.

borax, and one ounce of sweet spirits of niter or linseed oil may be used alone as a bath instead of using the above named bath.

In immersing the heated metal after the compound or powder has been placed thereupon into the solution above given, the tool or metal is hardened as in the ordinary tempering process, but by subjecting it to this solution composed of the ingredients named the metal or tool becomes very hard so that when the article has received the treatment it is a much tougher and harder article.

In hardening tools the tool may receive the treatment after it has been fashioned into its proper shape or the metal may be treated, before it is shaped or fashioned and then the tool fashioned into its proper shape.

From the foregoing it will be seen that I have provided means whereby metal and tools made of either steel or iron can be hardened and toughened without producing undue brittleness, and when applied to the tempering solution afterhaving received the compound upon the heated article it is hardened and toughened, creating a tool superior and more durable than any now on the market;

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The herein-described method of treating iron or steel consisting in treating the heated metal-to aowder compound containing borax and so a and then tempering the metal. I

2. A method for treating iron or steel consisting of treatin' the heated metal to a powder compoun containing borax, soda, and common salt and then subjecting the metal to the tempering process.

3. A method for treating iron or steel con sistin of treating the heated metal to a compoumf containing borax, soda, cobalt and common salt and then subjecting the metal to the tempering process.

.4. A method for treating iron or steel con- Patented (let-19, 190a. i

sisting in treating the heated article to fa I 5. A method for treating iron or steel con- I sisting in treating the heated article to a compound containing borax and soda, and then inserting the metal in a bath containing water lime, sal ammoniac, soda, and borax.

6. method for treating iron or steel consisting in treating the heated article to a compound containing borax and soda, and then'inserting the meta! in a bath containing water, lime, soda, borax, and sweetspirits of I niter.

7. A method for treating iron or steel con- I sisting in treating the heated metal to a comgound containing borax, soda, salt, and coba t, and then inserting the metal in a bath eontainin water, lime, sal ammoniac, soda, borax, an sweet s irits of niter.

' In testimony whereof aflix my signature, in the presence of two witnesses.

HENRY W. PARTIN.

Witnesses:

HERBERT C. EMERY, VERNON E. HODGES. 

